HDMI2C1-6C1 Datasheet, PDF (11/23 Pages) STMicroelectronics – ESD protection and signal booster for HDMI source control stage interface

HDMI2C1-6C1
Application information
2.5
Application block diagram
The Figure 10 shows a typical application block diagram proposal implementing all the
possible options. The diagram shows that the CEC driver can be totally independent from
the HDMI™ ASIC. In this way, even if the +5 V power supply and/or if the HDMI™ ASIC is
sleeping in stand-by mode, the CEC bus is still active in low power mode. In this way, the
designer has then the tools to optimize the power consumption of the global application in
stand-by mode, and at the same time, has the possibility to implement a smart wake-up
through the CEC bus enhancing the final user experience.
VDD_IC
over current
detect
HPD
DDC data
DDC clock
HEAC-
HEAC+
Figure 10. Application block diagram
VDD_IC _+5V
HDMI2C1- 6C1
R7
C3
C4
VDD_IC
R4
R5
VDD_CEC_IC
VDD_5V
VDD_IC
FAULT
HPD_IC
SDA_IC
SCL_IC
HEAC-
HEAC+
VDD_CEC_IC
CEC
driver
R6
C5
CEC_IC
GND
5V_OUT
HPD
SDA
SCL
Utility
VDD_CEC
CEC
C2
R3 R2
VDD_CEC
D1
C1
R1
+5V power
HPD / HEAC-
SDA
SCL
Utility / HEAC+
CEC bus
Note:
Table 1. Block diagrams references
Ref.
Typical values
Comment
R1
R2, R3
R4, R5
R6
R7
D1
C1 to C5
27 kΩ
Pull-up resistance on CEC bus, specified by the HDMI standard
1.8 kΩ
Pull-up resistances on DDC bus, specified by the HDMI standard
10 kΩ
Pull-up resistance on DDC bus, ASIC side, value selected to be
compliant with I2C levels
270 kΩ to 1 ΜΩ Pull-up resistance on CEC line, ASIC side
10 kΩ
Pull-up resistance on FAULT line (option)
BAT54
100 nF
Small schottky diode blocking backdrive current flowing toward the
V_{DD_CEC} supply
Decoupling capacitance on power supplies
SCL_IC, SDA_IC, and CEC_IC have to be driven with an ASIC working with open drain
outputs.
DocID025281 Rev 1
11/23
23